Latest advisory from Garland County Department of Emergency Management

Wednesday, August 29, 2012, 6:00 AM

As I suspected yesterday, the National Hurricane Center's projected track for Isaac has shifted farther west.  The current forecast calls for Isaac to enter southwest Arkansas very late Thursday night or during the wee hours of Friday morning, then progress through western Arkansas Friday and Friday night, exiting the state by the wee hours of Saturday morning.  Isaac is projected to be a tropical depression (sustained winds of 38 mph or less) as it crosses Arkansas.

I wouldn't concentrate too much on exactly where the center is going to go.  Most of Arkansas will be on the eastern side of the track, which is where the heaviest rain and tornadoes occur.

Rain and wind from Isaac should begin making it into the southern part of the state by early Thursday morning.  The heavier rains should spread to most of Arkansas, except the north, by Friday morning.  The heaviest rain should exit northern Arkansas Saturday morning.

I have attached a graphic from the Hydrometeorological Prediction Center showing expected rainfall amounts with Isaac.  As I have pointed out previously, do not take these amounts to be exact.  A shift in the path of Isaac will shift the axis of heaviest rain.  What I would take from the graphic is that a large area of heavy rain is expected across most of the state.  There will likely be at least a few totals greater than 6 inches.  Flash Flood Watches have already been posted for much of Arkansas.

Winds will generally be in the 20 to 30 mph range, with some gusts to 40 mph or so.  Winds may be a little stronger over parts of southern Arkansas.

As for the tornado threat, there should be none in Arkansas today or tonight.  On Thursday, best chances of seeing a few tornadoes will be in southern Arkansas.  On Friday, the tornado threat will encompass a large part of the state, although northeast and east central Arkansas appear to be the least likely areas.  Generally, tornadoes with tropical systems well inland tend to occur during the afternoon and early evening hours, with nighttime tornadoes much less common.

For reference, in 2008, Gustav brought two EF0 tornadoes to Arkansas, while Ike brought three EF0 tornadoes and six EF1 tornadoes.  Rita, in 2005, was more prolific with three F0, nine F1, and three F2 tornadoes.

• There are (3) basic interoperability solutions that cost nothing or very little:
1. Pre-program all mobile and portable radios with national interoperability frequencies in all radios (usually no infrastructure involved or required)                             
2. Share radio frequencies with neighbors on compatible radio systems (conventional or trunked radio systems); and
3. Drop most radio codes and adopt plain English communications for day-to-day transmissions. Remember, in an emergency, an agency will "play like they practice". Encourage mutual aid regularly, using radio communications.